| Runtime is gradually shorter than it was when new | Normal battery aging or reduced usable capacity | Rechargeable lithium-ion cells lose capacity over time and through charge cycles | The robot finishes the same task sooner despite similar workload and conditions | Compare measured runtime with the original specification and inspect battery health data if available |
| Battery percentage drops quickly during movement | The robot is drawing unusually high current | Blocked wheels, excess friction, steep surfaces, heavy loads, or repeated acceleration | Motors sound strained, wheels slip, or movement becomes slower than usual | Remove obstructions, clean moving parts, reduce the payload, and test on a flat surface |
| Battery drains while the robot is stationary | Standby power consumption is higher than expected | Wireless communication, sensors, displays, processors, or motors remaining active | A noticeable percentage is lost without driving or performing mechanical work | Enable sleep mode, close unnecessary processes, reduce wireless activity, and check for software faults |
| Battery level falls sharply near the end of a task | The battery voltage is sagging under load | High internal resistance caused by aging, low temperature, damage, or an unsuitable battery | The robot may slow down or shut off when motors start, then recover after resting | Test under the same load, allow the battery to reach room temperature, and replace a damaged battery |
| Runtime decreases mainly in cold conditions | Temporary low-temperature performance reduction | Cold temperatures reduce chemical reaction rates and increase battery internal resistance | Performance improves after the battery warms safely to room temperature | Operate and charge within the battery maker's stated temperature range |
| The robot reports a high charge level but runs briefly | The battery gauge may be inaccurate or poorly calibrated | The battery-management system estimates charge from voltage, current, and usage history | The displayed percentage changes suddenly or does not match measured runtime | Use the approved calibration procedure and check the battery-management system for errors |
| Charging takes longer while operating time becomes shorter | The battery may have increased internal resistance or a charging issue | Cell aging, poor thermal conditions, an incorrect charger, or a damaged charging connection | The charger remains in the constant-voltage phase for an unusually long time | Use the specified charger, inspect contacts, and stop using a swollen, hot, or damaged battery |
| Drain began after a software or firmware update | Power-management settings or task behavior may have changed | Higher sensor frequency, continuous networking, navigation recalculation, or a background process | Energy use changes without a corresponding change in the physical environment | Review update notes, compare power settings, and record runtime before and after changes |
| Battery becomes hot during charging or operation | Energy is being converted into excess heat or a safety fault may exist | Overcurrent, poor ventilation, damaged cells, charger problems, or mechanical overload | Temperature rises noticeably above normal operating conditions | Stop use if overheating, swelling, leakage, or unusual odor occurs and seek qualified service |